1. Field of Invention
The present invention relates to an emulsion type modifier. More particularly, the present invention relates to an emulsion type modifier for improving properties of the pressure-sensitive emulsion acrylic adhesives.
2. Description of Related Art
In general, the pressure-sensitive emulsion acrylic adhesives have inferior surface adhesion toward the low surface energy substrates, such as the polyolefins. Thus, tackifiers are usually needed for improving the adhesion of the pressure-sensitive emulsion acrylic adhesives. The representative tackifiers for the pressure-sensitive emulsion acrylic adhesives are the rosin resins. The rosin resins are in fact one type of acidic natural resins extracted from the pine trees. However, the quality of the rosin resins is not always stable and usually varies if obtained from different pine trees of various origins, from diverse weathers or numerous tree spices. Due to the compatibility of the rosin resins and the pressure-sensitive emulsion acrylic adhesives, the physical properties of the pressure-sensitive emulsion acrylic adhesives may be deteriorated if too much rosin resins are added.